Automatic slide projector with remote control for reversing travel direction of magazine



Jan. 19, 1965 E. ZILLMER ETAL AUTOMATIC SLIDE PROJECTOR WITH REMOTE CONTROL FOR REVERSING TRAVEL DIRECTION OF MAGAZINE Filed Nov. 19, 1962 V direction.

United States Patent A This invention relates to automatic slide projectors in which slides, mounted in a magazine, are sequentially projected responsive tol operation-of a remote control means. More particularly, the present invention is directed to a simpliiied remote' control means for such` an automatic slide projector, bylmeans or" which the direction of travel of tne magazine may be readily reversed for re-projecting a previously projected slide.

L1 a known type of automatic slide projector, the slides are mounted in a magazine which isradvanced longitudi- Y nally, in a'stepwise manner, by operation of a remotel control device. in the cycleof operation, a slide in the projection position is shifted back into the magazine, the

magazine is advanced by one step, andthe next slide is shifted out of the magazine to the projection position, the

arrangement being cyclically repeated Vunder the controly or" the remote control device.

in automatic slide projectors of this type, it is known to providespecial control arrangements whereby, when desired, the directionof travel of the magazine may be.

reversed so that a previously projected. slide may be rei projected. YHowever, known arrangements of this type j havefbeen rather complicated in operation', particulmly for an unskilled operator, and have been subject to l ready derangement and malfunction.

.The `present invention is directedato an automatic .slide projector of the aforementioned type in which there i s provided an exceptionally simple control means operable,-

injonefniode of operation, to advance the magazine inithe-normal step-bystep manner to successively project the slides, and further operable to reverse the direction *of travel of the magazine at will, and, responsivefto differentm'odes vof operation. of the Asame remotefcontrol device. l. More particularly, the

automatic-2 slide projector of Athe illustrating the magazine stepping and slide shifting means embodying the invention; and

EEG. 24 is a transverse vertical sectionaljview through the projector shown in FIG.A1. Y

Referring to the drawing, a projector housing l is illustrated as having a slide window 2 substantially centered transversely of theoptical axis of the projector, and adjacent which are rails 3 and 4 for supporting a slide 5 displaced from magazine 6 into a position covering the window 2. Displacement of slides 5 from` magazine 6, and return of the slides to the magazine, are elected by a known 'type of slide changer 7 which is reoiprocable transversely of the optical airis of theprojector. In the` drawings, slide changer 7 is illustrated in ythe position in which its arm or slide engaging means 3 has returned a slide 5 to magazine 6, the slide 5 having been returned from the rails 3 and 4 adjacent the slide window 2. The slide changer has a second arm which, upon movement of the'slide changer '7 to the right, as viewed in thedrawings, displaces a slide 5 from magazine 6 onto ,the support rails 3 and 4 for positioning the slide across` the f slide window 2.

The step-by-step advance of the magazine A6,1and the reciprocation of the slide changer '7, may beeiiected by any suitable power means. For'example, theV usual driving motor for the ventilator, for the projector may `be utilized for the driving of the-magazine and the reciprocation of the slide changer.y The vventilator` motor is generally providedwith a pulley ltl'tor engaging driving j As illusrneans'connecting the motor to the ventilator'. trated in the drawings, a cam plate il is lixedly secured to the pulley'l, the pulley 10 and thevcamvplatesll being.

rotatable as a unit 'onra shattlZmounted in a suitable bearing in the housing l... The Ventilator motor, of course,

operates continuallyl whenever thev projectorisy energized.'

ber fof' radially projecting" cam lingers 13.'

of somewhat,largenfdiameter than the main periphery ofv empleen. arriesgarsemediumfofappin is, disk'14 is connected to one end of a linkor connectingjrod :t6

invention is provided witha AVslide changerjwhich sre-',f

cipr'ocable transverselyto the ,direction of-travel ofthe magazine.V This slide'rcha'ge'r carries -a shiftable drive.. member which isV operable. :to .actuatey magazinei driving means for selective steppingfof the Amagazinein eitl'ier.v

directiomthe driveniembe'r having a'ilrst drive'positionin which, during eachfreciprocationof the slidechang'er, the dniving member, through suitable .magazine stepping mechanism,V advances the magazineone step in a forward direction. Therdrive member'has a second position, ,tol which it may be shifted atthe' will of the Voperaton'through .the medium of the remote control, and in which position, during .reciprocasion of theslide changer, thedrive mem- 'Der Willerect movement of the magazine in the reverse rlhiis selective shifting ofthe drive member r switching device to either of its drive positions is rperformed by the same remote control means which eliects the normal srtepi-by-step advance of the magazine `and the successive projection of the slides mounted therein.

z Por an understanding of the principles of the invention,.

reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing.- ln the drawing:

which, at its other end, is oscillatably connected to apin i7 oniheslide changer 7k. Thereby,.during each revolution of di'slrflg "ai single shuttling movementfor recipro'- cation ofl'slide'changer 7 Vis 'eiected-i-fln amannerlvto i be described,dislt lll may begselectively 'coupled'to'cai-n.,v plate il during a single rotationoffcam yplate lll. f Disk ,lli carries` a bearingl l on which ispivotally mountedaco'upling catch i9, coupling catch 19. being `so f Y connectedY to dislr that it 'resists displacement, Catch t i9 1carries a coupling pin 2@ which is Ycapable".,of being moved into Vthe path-of travel ottheradial'projectionsjor camwngers i3 ofi cam plate il. Byswinging movement of catch i9, thefpinfil may be moved either radiallyy cated bythe broken line illustration in FIGS; 1 and 2.

in thisposition of pin 20, there is no coupling between f j? cam plate Till and disk 14, and it willbe noted, fronill'G. `lhthat cam plate lll and disk 2id are arranged to rotateV in acounterclockwise direction'.- f.

Coupling of disk '14' to ,cam plate lLby engagementf of pin 2t) with` a radial carn tingenlgof Vcam plate .11,f.

Viseiected by pressing:a'button:2 3 of a remote c'ontrolfl switch unit 24, such*pressingV of button 23 closing a nor-ff g j mally oPSn switch v2S.,` Vvl/hen; 'switch'l-ZS is iclorsed, it i` energizes aisolenoid in the.housing'1,isolenoid 26 having. associated `therewith a spring -27 which'fnormally Patented dan. 19, 19515 Y vthe slide changer 7.:

biases an armatnre`28V outwardly away from solenoid 26. When solenoid 26 is energized, armature 28 is drawn into the solenoid and an arm 29 connected to the armature engages pin 2d to move the lattervinwardly so that it will be inthe path of travel of aiinger 13 of cam 11. This couples disk 14 to cam plate 11 so Ithat disk 14 is rotated counter counterclockwise through one revolution. Near the completion of this revolution, pin 2G engages xed cam 21 and is displaced outwardly to disengage the :finger 13 ofv cam plate 11, the rotational movement of cam 14 continuing until pin lZtl engages detent 22. This stops rotation of disk 1d.

The reciprocation ,of slide changer 7, by virtue of the rotation of disk 14 and throughthe medium of the link 16, not only eects shitting of a slide 5 out of magazine 6, into the projection position, and back to the magazine, but also effects an advance of magazine 6. This advance is effected during the motion of slide changer 7 to the left, as viewed in the drawing, wherein a slide 5 is removed from the rails 3 and 4 and restored to the magazine 6. In a known manner, magazine 6 is'provided with a rack 39 which is engaged by a ratchet wheel 31 rotatably mounted on a shaft 33 secured to housing 1 on the center line of reciprocation of slide changer 7, the ratchet wheel 31 being secured to rotate with an indexing wheel 32. Indexing wheel 32 carries a number of pins 3.4 equalV to the number of teeth of ratchet wheel 31. A spring biased detent 35' normally engages between adjacent teeth 35 so as to rele'a'sably maintain ratchet wheel 31 and indexing wheel 32 against rotation. in the position `in which ratchet V wheel 31 and indexing wheel 32 are held by detent 35,V aslide 5 is properly aligned for engagement by fingers Vand'9 of slide changer 7.

` arms 3%v and 40 are parallelto the directionof'reciprocation of the'slide changer. forked pawl A36 hasa pilot or guide arm 41 carrying 'a pin 42 which, under the bias' gof spring 33, is normaly aligned with the center line of It will be seenthat the reciprocation of vslide changer 7.

axis of Vturning which is provided forw the pawl36 bythe" pin 37 and the kaxis of turningwhich is provided for` the wheels 31 and 32 by the' shaft 331 are locate-din a plane which includes Vthe center line of reciprocation of A control armor guide camd is ciprocaton of slide changer '7. -Guide carri i3V has a pilot nose 44,fan'd carries a lshaft e5 whichfalso has secured` thereto a radiusfarm 46 connected byV a link 47 totheA armature 2S of solenoid 26. When solenoid 26 isdeenSrgiZed, pilot orh guide nose 4d o'ccupiesthe position shownin solid lines in FIG. l andfwhen solenoid 2,6 is energized, the pilot 'or guide noserdi occupy the position kshown .in dotted lines in BIG. l.

' The illustrated arrangement, as thus far'described,-fop cratesy in the following manner. When slide changer 7 -ismovedto the right to shift a slide 5 Y out of magazine 6 and `onto rails 3k and 4'adjacent slide window'Z; the pilot pin 42 ofthe forked pawl i565V is substantiallyin n mounted in housing Y 1 withiny the rangek of traveltof pilotpin d2lduring rea returned to its solid line position before pin 42 is moved to the left sufciently far to engage pilot or guide finger or nose de. Under these conditions, Vpin 42 is guided by nose d4- onto the edge 4S of guide cam 43. Forked pawl 35 .is thereby oscillated clockwise to the position shown in FIG. 1 wherein arm 39 engages one of the pins 34 yof indexing wheel 32. Upon continuation ofk the movement of slide changer 7 to the left to restore a slide 5 into the magazine 6, arm 39, overcoming the biasing force of the detent 3:3', moves indexing wheel 32 and ratchet 31 one step in a clockwise direction. This displaces magazine 6 in a forward direction by Vone step, the forward direction being toward the top of FIG. 1. Slide changer 7 then reverses its direction of movement to remove the next slide from magazine 6 onto rails 3 and d adjacent slide window 2.

When it is desired, during the changing of the slides, to move magazine 6 backward for the purpose of reprojecting a previously projected slide, all that is necessary is to maintain push button 23 depressed for a longer inu terval. Maintaining push :button 23 depressed for such longer interval maintains solenoid 26 energized for a longer interval so that pilot nose 44- of guide cam 43 is maintained in the dotted line position for a longer int ter-val. As a result, during lmovement of slide changer 7 to the left, pin 42, engaging pilot or guide nose 44, will be directed along the side 49 of guide cam 43. This will swing forked pawl 36 counterclockwise so that its arm liti' will engage a pin 34 of indexing wheel 33. Consequently, `upon continued movement of-slide 4changer 7 to the left, ,indexing wheel 32 andratched wheel 31 will be ro`- tatednone step ina counterclockm'se direction to move magazineV d longitudinally one step in the reverse direction. Thereby, the slideV 5 which has been previously projected may be re-projected, and the operation .may

be repeated for as many steps as desired by lrepeated longerduration pressings of the'push button 23.` It will be noted from the foregoing that,

porting means fortransportingthe magazine 6 either. in a vanced stepwise in a forward direction or may be stepped rearwardly #to repeat a showing of al previously projected j Vs lide. Thus, the ladditional switching means *previouslyj required for eifecting reverse motion of .magazine 6 to rre-project a slide is eliminated, and only a single and` Vvery simple remote control switchL device 24 'is needed` to Veffect both normal operation of the automatic slide projector and reverse motion of thel magazines.

. It will, be seen fromthe above description that the wheels 31and'32 form togetherwith 'thezrack 3? a trans.` porting ,meaiisV for transportingthe magazine either in a lforwardV direction orinr a reverse direction. @The rotary disk 14 together with the pin 15, the linkt16, 'the'v pin 17, and the -slide changer V7 forrnja ,drive means which,

once it is'set'into operationgcontinues tooperate through a 'complete cycle during which this drive means moves vfrom an'initial rest positionl alongia 'predetermined path to 'an end position distant fromthis rest position and I back to the rest position to complete its cycle of operathe area immediately above the magnet 26. Pin 2G of disklr extension 29, thereuponmove pin 2G. into the path of" vtravel of projecting cam'ngers 13 of cam plate 11. YAt the same time, pilot or guide nose is oscillated from the solid line position to the dottedline position momen` tarily and only during energization of solenoid 26.

If solenoid 245v is energized'ifor `only a brief interval,

.l the guide on pilot tongue 44 of guide cam 43 will have To change Ithe slide, solenoid tions-The pawl 36y forms aV transmission meansdwhich iscarried by the drive means for transmitting adrivo therefrom to the `wheels 31 and 32 so as to actuate the rack 30 for `advancing the magazine 6 in the forwardor the reverse direction. The transmission means 36V of course has one position Where the magazine will be advanced in a forward direction and a second position where the magazine willbe advanced in a reverse direction, and

the element 44 together with the cam 43 form a deflecting means capable of deilecting the transmission means 36into 'one or the other of its positions, this deliecting means .43, 44 being situated along the path ,lof movement` or" the transmission means 36 with the drive means once' n merely byV varying the operating time or mode of operation of. the

36 will be given a position which will control the direction of movement of the magazine. The solenoid 26 together with the manually operable assembly 24 form a manually operable means cooperating with the drive means for initiating a cycle of operations thereof and also cooperating With the deflecting means for moving the later simultaneously with the initiation of the operation of the drive means from a rest position where the transmission means will provide a forward direction of movements of the magazine to a second position where the deecting means will deect the transmission means to a position which will produce reverse movement of the magazine, and the movement of the transmission means 36 into engagement with the deiiecting means requiring a length of time which gives the operator the option of retaining the deflecting means in its second position or releasing the manually operable means so that the deiiecting means Will return to its rest position before the transmission means reaches the deflecting means, and in this way the operator has the option oi' providing either forward or reverse movement of the magazine. It is particularly to be noted that irrespective of the choice which is made Vby the operator in this way, at the end of a cycle of operations all of the parts return to their initial position so that the choice of the direction in which the magazine is to be moved mustbe made by the Ioperator at each operating cycle, and the structure will not operate to retain a direction of movement which is instituted by the operator during one cycle throughout successive cycles until again changed by the operator. Moreover, it is to be noted, as is clearly apparent` from FIG. l, that the distance between the indexing wheel 32 and the deiiecting means 4d is such that one or the other of the arms 39 and 40 of the pawl 36 will engage a pin 3d of the indexing wheel 32 almost immediately'after the deecting nose 44 engages the pin 42 for deiiecting the pawl 36 in one direction lor the other, so that the operator can observe the direction of movement ofthe magazine and will not maintain the solenoid 26 energized for an undesirably long time after the pawl 36 has been deflected in one direction or the other.

While a specic embodiment of the invention has been shown and described in detail to illustrate the application ofthe principles of the invention, `it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A slide projector comprising', in combination, a housing having a slide window substantially centered transversely of the optical axis of the projector, and slide support means adjacent said window; a slide magazine movable substantially parallel to said optical axis; a slide changer reciprocable transversely of said optical axis to transfer slides between said magazine and said support means; driving means, including means coupled to said slide changer, operable, when activated, to reciprocate said slide changer through a slide changing cycle; a single control means selectively operable to activate said driving means; magazine stepping mechanism, including a shiftable drive member reciprocable with said slide changer, operable, during each slide changing cycle, to step said magazine; said drive member, in a iirst position, stepping said magazine in one direction' and, in a second position, stepping said magazine in the opposite direction; and shifting means operable, responsive to one mode ot operation of said single control means, to shift said drive member to said iirst position and, responsive to another mode of operation of said Vsingle control means, to shift said drive member to said second position, said stepping mechanism including a ratchet wheel cooperable with-said magazine and yrotatably mounted on an axis situated in a plane Whichincludes the centerdrive member comprising-a=-forl ed pawl oscillatably t 5 t line of reciprocation thereof,v the arms of said forked pawl being normally spaced uniformly to either side ot such center line; said drive member, when shifted to said iirst position, having a iirst arm positioned to cooperate with said ratchet Wheel to -turn the same in one direction and, when shifted to said second position, having aV second arm cooperable with said ratchet wheel to turn the same in the opposite directiommeans biasing saidV forked pawl to a position in which its' forked arms extend in Y substantially parallel uniformly spaced relation to either side of the line of reciprocation of said slide changer, said forked pawl including a guide arm projecting radially from its center of oscillation in a direction opposite to the projection direction of its forked arms; said shitting means including a switching cam positioned in the path of movement of'saidguide arm duringfreciprocation of said slide changer and operable to shift said forked pawl to either said iirst position or said second position dependent upon the mode of operationof said single control means.

2. A slide projector comprising, in combination, a housing having a slide window substantially centered transversely of the optical axis of the projector, and slide support meansV adjacent saidfwlndow; a slide'magazine movable substantially'parallel to said optical axispa slide changer reciprocable transversely of said optical axis to transferslides .between said magazine and said support means; driving means, including means coupled to said slide changer, operable, when activated, to reciprocate said slide changer through a` slide changing cycle; a single control means selectively operable to activate said driving means; magazine stepping mechanism, including a shiftable drive member reciprocable with said slide changer, operable, during each slide changing cycle, to step said magazine; said drive member, in a rst position, stepping said magazine in one direction and, in a second position, stepping said magazine in the opposite direction; and shifting means operable, responsive to onefrnode of operation of said single control means, to shift said drive member to said iirst position and, responsive to another mode of operation of said single control means, to shift said drive member `to said second position, said driving means including a substantially circular cam plate continuously rotated during l energization of said projector, said plate having radially projecting cam fingers; a rotatable disk coaxial with said cam plate and vv rotatable independently of the latter; means connecting said disk to said slide changer to reciprocate said slide changer through one cycle during each rotation of said disk; a pin carried by said disk and movable into and out of fthe path of travel of said projecting cam lingers; xed cam means operable, at the,

end of each rotationof said disk, to move said pin out l of the path ot travel of'said cam lingers; a iixed stop engageable with said pin upon movement of the latter out of such ,path of travel; said controlV means,when operated, displacing said pin out of engagement with said fixed stop and into the path or travel of said Aprojecting cam lingers. Y

3. A slide projector, as claimed in claim 2, said control means including a solenoid; anormally'open switch LA slide projector, asuolaimed in claim 3, inlwhich sm'd drive'rnember shifting'means comprises arswitching Y line of reciprocation of said-slide changer; said shiitablc"V n cam oscillatablymounted about an axis situated in av n plane which includes the centerline of reciprocation of-` said slide changer; means connecting said switching cam the path of travel of said cam to said armature whereby, in the retracted position of said armature, said switching cam is positioned to shift said drive member to said first position and, when said solenoid is energized, said switching cam is positioned to shift said drive member to said second position.

5. A slide projector, as claimed in claim 4, in which said magazine stepping means comprises a ratchet Wheel rotatable about an axis substantially on the center line of reciprocation of said slide changer; said shiftable drive member-comprising a forked pawl oscillatably mounted on said slide changer at substantially the longitudinalv center line of its reciprocation and having a pair of forked arms which are substantially parallel and which we selectively cooperable with said ratchet wheel to rotate the latter in either direction depending upon the position of said forked pawl; said forked pawl having a guide nose extending from its centery of oscillation in a direction opposite to its forked arms; said shifting means including a switching cam oscillatably mounted in said housing in the path of movement of said forked pawl; said guide nose havingapin engageable with said shifting cam; said shifting cam being disposed intermediate the limits of movement of said pin during reciprocation of said slide changer.

6. A slide projector, as claimed in claim 5, said pin, at the limit of movement of said slidechanger in the direction moving a slide onto said support means, being disposed at a substantial distance from said switchV cam; said switch cam, when said solenoid is deenergized, occupying a position in which, upon engagement thereof by said pin, said forked pawl will be shifted to said firstv position in which it rotates said ratchet wheel, in a direction to advance said slide and, during energization of said solenoid, being shifted to a position in which, uponV engagement thereof by said pin, said forked pawl is shifted to said second position in which it rotates said ratchet wheel to move said magazine in a retracting direction; the distance of said switch cam from said pin, when said slide changer is at the limit of movement in the direction moving a slide onto said support means, being such that, upon momentary energization of said solenoid, switch cam is first moved to said second-mentioned position thereof and then. returned kto said first-mentioned position thereof before engagement of said switch cam by said pin; said switch cam, upon sustained energization of said solenoid during travel of said slide changer in a direction to transfer a slide to the magazine, remaining in said second-mentioned position thereof so that, upon such sustained energization of said solenoid, said forked paw] will be shifted to a position in which it moves said magazine in the reverse direction.

7. A slide projector, as claimed in claim 6, in which said switching cam comprises a member having a pair of parallel side edgesy substantially parallel to the direction of reciprocation of said slide changer, the portion of said switching cam having said side edges extending from the pivot point of said switching cam toward said magazine; sm`d switching cam having a portion projecting from its pivot point in a direction away from said magazine and formed as a tapered nose for engagement With said pin.

8. In a slide projector, ysupport means for supporting Y a magazine for forward or reverse movement, transporting means carried by said support means for transporting a magazine either in a forward or reverse direction, drive means having a rest position and moving automatically through the complete cycle of operations along Vthe given path from said rest position to an end position and back to said rest position once a cycleV of operations of said drive means has been initiated, transmission means carried by said drive means for movement therewith along said path and having one yposition in which said transmission means cooperates with said transporting means to move said magazine forwardly and said transmission means having a second position where it cooperates with said transporting means for actuating the latter to move said magazine inV a reverse direction, deecting means situated in the path of movement of said transmission means when the latter moves with said drive means after a cycle of operations of said drive means has been initiated, said deflecting means having a rest position where it cooperates with said transmission means to maintain the latter in said one position thereof for providing forward movement of said magazine and said deiiecting meansrhaving a second position where it is situated in the path of movement of said transmission means to deflect the latter into its second posit-ion for providing movement of said magazine in said reverse direction, and manually operable means cooperating with said drive means for initiating a cycle of operations thereof and also cooperating with said deiiecting means for displacing the latter from said rest position thereof to said second position thereof, said deflecting means automatically returning to its rest position when the operator releases said manually operable means and the time required for said transmission means to move into engagement with said deilecting means being sutiiciently great to permit the operator to release said manually operable means before said Itransmission means reaches said deflecting means so as to provide forward movement of the magazine or to retain said manually operable means active until after said deiiecting means is engaged by said transmission means so that said deiiecting means will in this way be maintained in its second position deflecting said transmission means to its second position providing reverse movement of the magazine.

9. In a slide changer as recited in claim 8, the distance between said deliecting means and transporting means being small enough toy provide actuation of said transporting means by said transmission means almost immediately after said transmission means has been engaged by said deiiecting means.

10. In a slide changer as recited in claim 8, biasing means operatively connected to said transmission means for releasably holding the latter in a neutral position between said one .and said second positions thereof and said deiiecting means deflecting said transmission means from said neutral position either into said one position of said transmission means or into said second position thereof ldepending upon whetherv the operator has released said manually operable means before said transmission means has reached said derlecting mems, said biasing means returning said transmission means to said neutral position thereof at the end of each cycle of operations of said drive means.

11. In a slide changer as recitedY in claim 8, said drive means forming part of a slide changer for moving a slide away from and back to the magazine.A

12. In a slide changeras recited in claim 8, said manu- References Cited by the Examiner UNITED STATES v PATENTS 3,059,360 Vio/sz Krauskopf ss-zs X 3,072,016 1/63 Mscammon ss-zs A Y ort-1ER REFERENCES l German .applicationV No. 1,106,520, May 10, 1961.

NORTON ANSI-IER, Prinmry Examiner.

WiLLiAl MSEK, Examiner. 

1. A SLIDE PROJECTOR COMPRISING, IN COMBINATION, A HOUSING HAVING A SLIDE WINDOW SUBSTANTIALLY CENTERED TRANSVERSELY OF THE OPTICAL AXIS OF THE PROJECTOR, AND SLIDE SUPPORT MEANS ADJACENT SAID WINDOW; A SLIDE MAGAZINE MOVABLE SUBSTANTIALLY PARALLEL TO SAID OPTICAL AXIS; A SLIDE CHANGER RECIPROCABLE TRANSVERSELY OF SAID OPTICAL AXIS TO TRANSFER SLIDES BETWEEN SAID MAGAZINE AND SAID SUPPORT MEANS; DRIVING MEANS, INCLUDING MEANS COUPLED TO SAID SLIDE CHANGER, OPERABLE, WHEN ACTIVATED, TO RECIPROCATE SAID SLIDE CHANGER THROUGH A SLIDE CHANGING CYCLE; A SINGLE CONTROL MEANS SELECTIVELY OPERABLE TO ACTIVATE SAID DRIVING MEANS; MAGAZINE STEPPING MECHANISM, INCLUDING A SHIFTABLE DRIVE MEMBER RECIPROCABLE WITH SAID SLIDE CHANGER, OPERABLE, DURING EACH SLIDE CHANGING CYCLE, TO STEP SAID MAGAZINE; SAID DRIVE MEMBER, IN A FIRST POSITION, STEPPING SAID MAGAZINE IN ONE DIRECTION AND, IN A SECOND POSITION, STEPPING SAID MAGAZINE IN THE OPPOSITE DIRECTION; AND SHIFTING MEANS OPERABLE, RESPONSIVE TO ONE MODE OF OPERATION OF SAID SINGLE CONTROL MEANS, TO SHIFT SAID DRIVE MEMBER TO SAID FIRST POSITION AND, RESPONSIVE TO ANOTHER MODE OF OPERATION OF SAID SINGLE CONTROL MEANS, TO SHIFT SAID DRIVE MEMBER TO SAID SECOND POSITION, SAID STEPPING MECHANISM INCLUDING A RATCHET WHEEL COOPERABLE WITH SAID MAGAZINE AND ROTATABLY MOUNTED ON AN AXIS SITUATED IN A PLANE WHICH INCLUDES THE CENTERLINE OF RECIPROCATION OF SAID SLIDE CHANGER; SAID SHIFTABLE DRIVE MEMBER COMPRISING A FORKED PAWL OSCILLATABLY MOUNTED ON SAID SLIDE SHIFTER AT SUBSTANTIALLY THE CENTER LINE OF RECIPROCATION THEREOF, THE ARMS OF SAID FORKED PAWL BEING NORMALLY SPACED UNIFORMLY TO EITHER SIDE OF SUCH CENTER LINE; SAID DRIVE MEMBER, WHEN SHIFTED TO SAID FIRST POSITION, HAVING A FIRST ARM POSITIONED TO COOPERATE WITH SAID RATCHET WHEEL TO TURN THE SAME IN ONE DIRECTION AND, WHEN SHIFTED TO SAID SECOND POSITION, HAVING A SECOND ARM COOPERABLE WITH SAID RATCHET WHEEL TO TURN THE SAME IN THE OPPOSITE DIRECTION, MEANS BIASING SAID FORKED PAWL TO A POSITION IN WHICH ITS FORKED ARMS EXTEND IN SUBSTANTIALLY PARALLEL UNIFORMLY SPACED RELATION TO EITHER SIDE OF THE LINE OF RECIPROCATION OF SAID SLIDE CHANGER, SAID FORKED PAWL INCLUDING A GUIDE ARM PROJECTING RADIALLY FROM ITS CENTER OF OSCILLATION IN A DIRECTION OPPOSITE TO THE PROJECTION DIRECTION OF ITS FORKED ARMS; SAID SHIFTING MEANS INCLUDING A SWITCHING CAM POSITIONED IN THE PATH OF MOVEMENT OF SAID GUIDE ARM DURING RECIPROCATION OF SAID SLIDE CHANGER AND OPERABLE TO SHIFT SAID FORKED PAWL TO EITHER SAID FIRST POSITION OR SAID SECOND POSITION DEPENDENT UPON THE MODE OF OPERATION OF SAID SINGLE CONTROL MEANS. 